1. Field of the Invention
The present invention relates to a fuel cell, having a first electrode, a second electrode, and a membrane element, in which the membrane element is disposed between the first electrode and the second electrode, at least one of the electrodes has a flow field plate, and at least one flow conduit through which a reactant can be conducted extends in at least one outer surface of the flow field plate. The invention moreover relates to a flow field plate. The invention relates as well to a method for producing a flow field plate for use in a fuel cell.
2. Description of the Prior Art
Known fuel cells serve to convert hydrogen into usable electrical energy. To perform this electrochemical reaction, the fuel cell has two electrodes, at which two reactants, such as hydrogen and oxygen, are delivered to the fuel cell. The hydrogen delivered to one electrode—the anode—splits, yielding electrons in the form of H+ ions. While the electrons can be used, via an external current circuit, for generating energy, the protons diffuse through a membrane element to the second electrode—the cathode. At the cathode, a reaction of the protons with oxygen can then ensue, thereby producing water. Between each of the electrodes and the membrane element is a respective gas diffusion layer. This gas diffusion layer has the function of distributing the fuels, that is, hydrogen or oxygen, uniformly over the entire surface of the electrodes and to remove the products of the reaction, that is, current, heat, and water, from the electrodes. To speed up the reaction of the fuels at the electrodes, a catalyst can be introduced into the gas diffusion layer. If the catalyst is to be active in the fuel cell, the individual particles of the catalyst must be in contact with the membrane element and one of the fuels, and they must also be electrically conductively connected to the current collector element. If on or more of these conditions is not met, the catalyst particle is not active. Since the gas diffusion layer is typically produced from relatively coarse graphite fibers and the catalyst is introduced into deep regions of the gas diffusion layer as well, contact between the membrane element, the catalyst and the fuel cannot always be assured. As a result, a large proportion of the introduced catalyst is inactive.